If you wish to target an audience that has been seen at an event, there are a couple things to keep in mind.
Bi-weeky Releases
Foursquare re-processes and releases new Audience data to the Designer on a biweekly basis, meaning that you will need to wait ~2 weeks for new dates to be added to the available lookback window. Please keep this in mind when planning your event strategy and retargeting specific dates.
Since there is a minimum size of 10K devices to deliver an Audience, you may need to expand your segment criteria to increase the audience count
Helpful Event Targeting Reminders
When an Audience contains under 10,000 devices, it is not buildable and Foursquare recommends adding in visitation to POIs where event attendees are spending their downtime. One way to do this is to filter your desired categories, such as Hotels or Coffee Shops, using the venue zip code.
Reach Multiplier
You can also use the Reach Multiplier tool, which leverages machine learning to double the number of devices for the audience. Learn more about Reach Multiplier in the FAQ.
